I haven't had anything severe. A sibling pushed me off a trampoline onto a rock when when I was little, and I still have the scar on me knee. A couple solder burns that scarred. Oh, and there was this one time I owed a guy a lot of money, but "fortunately" he was a sadist, so he let me pay him back by letting him go to town on my stomach with a mallet. Didn't actually damage anything though.